Drying apparatus and process of drying



y 30. J. J. BERRIGAN El" AL 1,770,727

I DRYING APPARATUS AND PROCESS OF DRYING Filed May 9, 192B 4 Shuts-Sheet l July 15, 1930. J. J. BERRIGAN Er AL 1,7

DRYING APPARATUS AND PROCESS OF DRYING Filed May 9, 1928 4 Shoots-Sheet 2 77259215155 H Mia/ 14mm.

July 15, 1930. J. J. BERRIGANEI'AL 1,770,721

DRYING APPARATUS AND PROCESS OF DRYING Filed May 9, 192B 4. Shots-Sheet 5 y 15, 1930- I J. J. BERRIGAN ET AL 1,770,127

DRYING APPARATUS AND PROCESS OF DRYING Filed May 9, 1928 4 Shoots-Sheet 4 35 away, taken on the line 2-2 9 Patented July 15, 1930.

; UNITED STATES PATENT OFFICE I JOHN J'. BERRIGAN JOHN B. BERRIGAN', OF MILWAUKEE, WISCONSIN, ASSIGNORS OF ONE-THIRD TO KATHERYNE"P. MALON, OF MILWAUKEE, WISCONSIN; SAID JOHN B. IBERRIGAN ADMINISTRATOR OF SAID JOHN J. BERRIGAN, DECEASED.

name APPARATUS AND raocnssor DRYING Application filed May a, 1928. Serial Iva-276,420.

This invention relates to an apparatus and a method for drying and pulverizing plastic material such as clayey substances, particularly-the activated sludge from sewage disposal plants. 1 I

The purposes of the invention include the object of. overcoming objections to costly and slow methods now available for rendering. activated sludge, from filtering presses, into the dry and pulverized condition required for marketing as a fertilizer. Another object of the invention is to increase the rapidity of drying and pulverizing processes for treatment of plastic material by simultaneously compressing or squeezin water outof the material, drawin 1t over 'ghly heated surfaces, and subjectingit to the action'of hot air or' other moisture removing medium. It is also an object of the invention to avoid bringing the material treated into direct contact with flame. A further object of the invention is to rapidly raise'the temperature of the substance treated both by mechanical pressure and by causing it to rapidly pass 2 over incandescent surfaces of large area, so that the water content is instantly converted into steam, thus vastly increasing the pressure and disintegrating the material as the steam forces its way outwardly.

Apparatus forjcarrying out the invention is illustrated in the accompanying drawing in which: i

Figure 1 is a plan view of the machine. Fig. 2 is a vertical section {partly broken Fig. 1. Fig. 3 is a vertical sectional view partly grokeln away and taken on the line 3-3 of 1g. w

"Fig. 4 is an enlarged sectional detail in plan taken on the line 4-4; of Fig. 2, and shows the construction of the 'dryingunit through which the material is fed during the process of treatment.

Fig. 5 is a detail partly broken away and in vertical section taken on the line 55 of.

for forcing the sludge ormaterial treated enclosed, spaced inwardly from the walls, a

The invention broadly considered, consists in the provision of a plurality of narrow passageways, the walls of which are of large area and highly heated. Means are provided through these passageways. .Heated air is applied and outlets are provided for the air and also for the steam generated in the material. The means for forcing the'material through the passageways comprises reciproeating bladeswhich extend the full length of the passageways and work the material through by a grinding and rubbing action along the heated surfaces. The latter are maintained at t e highest temperature near the entrance'en in order to promptly surface-dry the material as it is being torn apart on shredded by the blades. Toward the outlet end' the temperature is decreased, so that the material treated, as it becomes dried, is not burned.

Referring to the drawings, the walls of the furnace'structure are indicated at 1 and drying compartment or unit 2 extending from the top to the bottom of the furnace and composed of a plurality of metallic partitions 3 to provide narrow passageways 4. for material which is to be'treated. The fur-.

nace ispreferably a gas or oil burner so that 86 the temperature of the unit 2 maybe regulated as desired and maintained at a higher temperature towards its upper on entrance end than. at its lower or discharge .end. Oil burner nozzles are indicated at 5 near the upper end of the furnace. The'passageways 4 are suppliedwith a moisture removmg medium such as air under pressure and prefer,-

ablyheated. The air may be heated by coils 6 located in the outlet flue 7 forgases of com- 99 bustion. Air from a compressor not shown'ls carried'to coil. 6 through the conduit 8 and from the coil G'the air is delivered by the conduits 91.0 the drying unit 2. The conduits 9 are each controlled by. a valve-.10.

.Air from these conduits enters the unit. 2

at the passageway 4 nearest'tlrei end wall 11 of the drying .unit and from thls passageway ,works its way to the remaining assageways 4 through the apertures 1 2.1n* t e partit on unit 2 in a similar manner through the conduits 9' which communicate with the heating coil 14 in an air and steam outlet flue 15 which carries away the vapor driven from the material treated by communicating with a transverseflue 16which, through the passageway 17 formed around the unit 2, communicate's with each of the narrow vertical passageways 4.

The material to be treated is forced into the passageways 4 at the upper end by means of a rectangular piston 18 which is reciprocated in the piston chamber 19 formed by the casting 20 mounted on the top of the furnace. The materi'al is delivered to thepiston chamher 19 through the hopper 21 when the piston is at-th upper end of its stroke and is forced by e piston under high pressure into the passageways 4. The piston acts as a valve to shutoff communication with the hopper 21'whenat the lower part of its stroke as indicated in Figs. 2 and 3 by closing the inlet 22 (Fig. 3). The mathrial treated is worked downwardly through the passageways 4-by blades 23 which reciprocate with the piston 18 and are secured thereto by fastening means 24. The blades 23 are guided by shoulders 25 on the partition walls 3. These shoulders extend from end to end of the partition walls andseparate the passageways 4 from thepassageways 26 which serve to carry the used air and vapor upwardly to the passageway 17 communicating with the outlet flue 16. The air and 'vapor or steampasses out of the passageways 4 to the passageways 26 between the blades 23 and the- -sl1 oulders.25. The blades 23 are provided w1th a series; of openings 27 which openings are bounded on their u per sides with the flat edges 28 of the bla es (Fig. 6) and at the bottom by sharpened edges 29. The flat edges 28 on the down stroke of the blades serve to drag the material downwardly and on the return stroke the sharpened edges 29 cut through the material, offering less resistance and therefore the material is fed progressively downward. The blades-are also provided with el'on ated slots 30 to provide space without inter erencefor the transverse combustion tubes 13.

The piston and the blades attached thereto are reciprocated by crank 31 mountedin the bearings 32 at the 'top of the machine 'and---'connected to the piston by connecting In the operation of the device, the wet 7 material which is to be dried is continuously fed: into the hopper 21 and falls below the piston 18 when at the upper part of its stroke. At each stroke the piston cuts off a portion of the material and forces it into the passage ways 4 .where' it is acted upon by the reciprocating blades 23 and rapidly worked dewnwardly first over red hot surfaces of par-' titionwalls 3, then along areas of these walls which areof decreasing temperature toward the bottom. The heated surfaces of the par-- tition walls serve to first surface-dry the material as it is bein pulverized by the rubbing action of the b%ades. These plates 23 are kept hot b conduction from their exosed lateral e ges as will be apparent from ig. 4. .As these plates move up and down, they reciprocate relative to and rub against the material to be dried, as the latter 1s fed gradually downward by comparatively short ste s, consistent with the small intake for eac depression of the piston. The steam generated increases the pressure. The heated air delivered through the conduits 9 is also preferably under considerable pressure and escapes with the steam upwardly through passageways 26. I

The burner nozzles are located near the upper end of the furnace in order to quickly apply a high temperature to the wet material as it-is received. As the material becomes drier it is subjected to less temperature atithe lower part of the furnace. In

treating sludge, the machine is preferably 1. The process of drymg andpulverizing plastic material which consists in rubbing the material in a'thinlayer by a relative reciprocating' motion under pressure over a highly heatedjjsurface afidusimultaneously subjecting the material to a current of moisture removing medium. v

2.- The process of drying and pulverizing plastic material which consists in injecting a heated, moisture removing mediuminto said material and forcing the material in a thin layer under-pressure over a highly heated surface. y i

3; The process of drying plastic material which consists in compressing and dragging the material over a highly heated surface, and forcing a moisture removing medium therethrough. I

4. The process of drying plastic material which consists in dividing the material into a plurality of thin layers, injecting a heated moisture removing medium therein, and forcing said layers under pressure over highly heated surfaces.

0 Signed at Qhic ago this 7th day of May,

1928. JOHN J. BERRIGAN.

JOHN B. BERRIGAN, 

